1. Re-recognize mathematical concepts, deeply understand their connotation and extension, and distinguish easily confused concepts. Taking the concept of "angle" as an example, there are many kinds of "angles" in textbooks, such as the oblique angle of a straight line, the angle formed by two lines of different planes, the angle formed by a straight line and a plane, the principal value of a complex angle, the included angle, and the chamfer. There is a certain range of values. For example, the angle formed by two straight lines in different planes is an acute angle or a right angle, not an obtuse angle, which ensures its uniqueness. If you understand and master this point, there will be no conceptual mistakes.

2. Deepen the understanding and mastery of theorems and formulas step by step, and pay attention to the applicable conditions and scope of each theorem and formula. If the average inequality is used to find the maximum value, three conditions must be met, all of which are indispensable. Some students make mistakes because they are not familiar with the structure of mean inequality or ignore the conditions it should meet.

3. Master the ideas and methods embodied in typical propositions. For example, the proof method of equality provides a general method to find the sum of coefficients of binomial expansion or polynomial expansion.

Therefore, correct thinking, careful reading, comprehensive mastery, combined with other materials and exercises, deepen the understanding of basic knowledge, thus laying a solid foundation for improving problem-solving ability.

Second, good classes: the quality of classroom learning directly affects academic performance.